This metadata record describes the production
of (48) 15' tiles in Cells 168, 169, and 170
for the Alaska Mid-Accuracy DEM.Fugro EarthData
completed all phases of production,under contract
to USGS, S/C-G10PC00013-01. USGS Task Order G10PC00013.

Purpose:

USGS contracted the production of this dataset for the
purpose of assessing the use of GeoSAR Interferometric
Synthetic Aperture Radar (IFSAR) in mapping the state of
Alaska.

Fugro EarthData established a fixed base station used for
differential global positioning of the aircraft during
acquisition. The base station was located at Fairbanks
International Airport outside Alaska Aerofuel, Inc. Precise
Latitude 64 49 39.2473 (dms), Longitude -147 50
57.4889 (dms), Ellipsoidal Height 143.260 (m).

Logical_Consistency_Report:

Any anomalies in the GeoSAR DEM such as noise, spikes,
or wells are remediated during a DEM inspection.
Proprietary Fugro EarthData software is used to remove
identified pixels and interpolate the voids; ensuring
logical consistency of the GeoSAR DEM. LiDAR profiler
data is used to validate the consistency of the GeoSAR
DEM. The GeoSAR DEM, GeoSAR ORI, GeoSAR DTM
and GeoSAR DSM are computed using the same bundle
adjustment to ensure co-registration between products.

Completeness_Report:

The data is checked for completeness by ensuring that the
GeoSAR DEM, ORI, DTM and DSM cover the entire
project area. Due to processing differences between the ORI and DEM data,
there are some islands present in the ORI data that have elevation data in
the DEM equal to the water surrounding the islands. These areas have purposely
been left as islands in the ORI data and filled with hydro elevation values in
the DEM data. Voids found in the GeoSAR DEM are filled by interpolation or
adjusted elevation data from the National Elevation Dataset (NED) using
proprietary Fugro EarthData software. All voids are recorded in the
Voids_With_Fill_Surface shapefile. The islands mentioned above are identified
in the void shapefile as filled with GeoSAR Hydro Elevation.

Positional_Accuracy:

Horizontal_Positional_Accuracy:

Horizontal_Positional_Accuracy_Report:

Prior to acquisition ground reflectors were placed in project
area and surveyed for their precise location. Proprietary
Fugro EarthData software is used to locate reflector sites in
GeoSAR DTM and DSM. Reflector locations in GeoSAR
DTM and DSM are compared to surveyed ground
locations using proprietary Fugro EarthData software to
evaluate horizontal accuracy.
Reference Quality Report for results.

Vertical_Positional_Accuracy:

Vertical_Positional_Accuracy_Report:

LiDAR profiler data is automatically filtered to select points
in open terrain throughout the project area. The filtered
LiDAR data set is then used as control points in analyzing
the vertical accuracy of GeoSAR DTM and DSM.
Proprietary Fugro EarthData software is utilized for
comparing the GeoSAR DTM and DSM to LiDAR control
points.
Prior to acquisition ground reflectors were placed in project
area and surveyed for their precise location. Proprietary
Fugro EarthData software is used to locate reflector sites in
GeoSAR DTM and DSM. Reflector locations in GeoSAR
DTM and DSM are compared to surveyed ground
locations using proprietary Fugro EarthData software to
evaluate vertical accuracy.
Reference Quality Report for results.

Once the motion data and respective raw data were
collected and delivered, an initial quality check was
performed. Preliminary MMP (Motion Measurement
Processing) is a proprietary program in which the motion
data of each segment was analytically viewed in
graphical form for the determination of which data was
within specifications and therefore should be used in
product. At this point the acceptable raw data were
registered to the motion data as 32 bit magnitude and
elevation files and were ready to be unwrapped, viewed,
and edited.

Process_Date: 20121001

Process_Contact:

Contact_Information:

Contact_Organization_Primary:

Contact_Organization: Fugro EarthData, Inc.

Contact_Person: Joseph Jones

Contact_Position: Project Manager

Contact_Address:

Address_Type: mailing and physical address

Address: 7320 Executive Way

City: Frederick

State_or_Province: MD

Postal_Code: 21704

Country: USA

Contact_Voice_Telephone: 301-948-8550

Contact_Facsimile_Telephone: 301-963-2064

Contact_Electronic_Mail_Address: jjones@fugro.com

Hours_of_Service: Monday - Friday, 8:00am - 5:00pm

Process_Step:

Process_Description:

Each flight line contains 4 swaths; a right looking X-Band
swath, a left looking X-Band swath, a right looking P-Band
swath and a left looking P-Band swath. Each segment is
setup for and interferometric processing and edited for
anomalies, artifacts, dropouts and incorrect ambiguities.
Finally, a proprietary radiometric program was run to
balance intensity values and the segments were ready for
mosaicking.

Process_Date: 20121203

Process_Contact:

Contact_Information:

Contact_Organization_Primary:

Contact_Organization: Fugro EarthData, Inc.

Contact_Person: Joseph Jones

Contact_Position: Project Manager

Contact_Address:

Address_Type: mailing and physical address

Address: 7320 Executive Way

City: Frederick

State_or_Province: MD

Postal_Code: 21704

Country: USA

Contact_Voice_Telephone: 301-948-8550

Contact_Facsimile_Telephone: 301-963-2064

Contact_Electronic_Mail_Address: jjones@fugro.com

Hours_of_Service: Monday - Friday, 8:00am - 5:00pm

Process_Step:

Process_Description:

Common points between overlapping swaths are
automatically determined using proprietary Fugro EarthData
software. Using these common points, a best fit solution is
determined. Swaths are combined using the best fit
solution to create final GeoSAR ORI, GeoSAR DSM, and
GeoSAR DTM mosaics; during this process the swaths are
converted from a local coordinate system to a global
coordinate system. The finished mosaics are inspected
and packaged for delivery. The final GeoSAR ORI,
GeoSAR DSM, and GeoSAR DTM products are delivered
as GeoTIFF files.